1. Field of the Invention
The present invention relates generally to a heat sink, and more particularly to a heat sink used for an LED lamp.
2. Description of Related Art
With the continuing development of scientific technology and the raise of people's consciousness of energy saving, LEDs have been widely used in the field of illumination due to their small size and high efficiency. It is well known that an LED lamp with LEDs arranged side-by-side in large density generates a lot of heat when it emits light. If the heat cannot be quickly removed, the LED lamp may become overheated, significantly reducing work efficiency and service life thereof.
A conventional heat sink which is used to absorb heat of the LED device is shown in U.S. Pat. No. 6,517,218. The heat of the LED device is transferred to a base of a heat dissipater at first, and then is dissipated to ambient air in a natural convection manner by fins of the heat dissipater. However, it is difficult to dissipate a large amount of heat accumulating in a bottom portion between the base and the fins, because airflow can not substantially flow through the bottom portion in the natural convection manner. Moreover, the conventional heat sink always has a great size in order to achieve a large amount of heat dissipation area.
What is needed, therefore, is a heat sink used in an LED device which has an improved heat dissipation efficiency.